The technical field of this invention is magnetometry and, in particular, the spatial interrogation of materials to deduce their physical properties from measurements of complex permeability and conductivity.
Magnetometers or arrays of coils have been used for noninvasive measurement of kinematic and physical properties of conducting materials. For example, eddy current sensors have been used to measure the thickness of conducting strips, as disclosed in Soviet Patents 573,609 and 502,205. Another use of such eddy current sensors has been in flaw detection, as disclosed in U.S. Pat. No. 3,939,404. However, the utility of these sensors typically is limited by their inability to provide enough information to resolve distributions of parameters.
There exists a need for better permeability/conductivity measuring devices and methods. In particular, there exists a need for better devices and methods for conducting non-destructive interrogations of materials to determine their physical properties across a spatial profile.